An electricity storage device includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and an electrolyte that includes an organic crystal layer including a layered structure and an organic solvent introduced into the organic crystal layer and that is interposed between the positive electrode and the negative electrode to conduct alkali metal ions. The layered structure includes an organic backbone layer containing an aromatic dicarboxylic acid anion having an aromatic ring structure, and an alkali metal element layer containing an alkali metal element that is coordinated with oxygen contained in a carboxylic acid of the organic backbone layer to form a framework. At least one of the positive electrode and the negative electrode adsorbs and desorbs the ions to store and release electric charge.

An electricity storage device includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and an electrolyte that includes an organic crystal layer including a layered structure and an organic solvent introduced into the organic crystal layer and that is interposed between the positive electrode and the negative electrode to conduct alkali metal ions. The layered structure includes an organic backbone layer containing an aromatic dicarboxylic acid anion having an aromatic ring structure, and an alkali metal element layer containing an alkali metal element that is coordinated with oxygen contained in a carboxylic acid of the organic backbone layer to form a framework. At least one of the positive electrode and the negative electrode adsorbs and desorbs the ions to store and release electric charge.

According to one embodiment, provided is an electrode group including a stack that includes a positive electrode and a negative electrode. A first width of the positive electrode active material-containing layer of the positive electrode in a first direction is smaller than a second width of the negative electrode active material-containing layer of the negative electrode in the first direction. The electrode group has a wound structure where the stack is wound along the first direction. A length L corresponding to a difference between the second and first widths, a mass per unit area M.sub.a of the negative electrode active material-containing layer, and a ratio p/n of a capacity p of the positive electrode to a capacity n of the negative electrode satisfy a relationship of 40 mg/m≤(L×M.sub.a)/(p/n)≤60 mg/m.

According to one embodiment, provided is an electrode group including a stack that includes a positive electrode and a negative electrode. A first width of the positive electrode active material-containing layer of the positive electrode in a first direction is smaller than a second width of the negative electrode active material-containing layer of the negative electrode in the first direction. The electrode group has a wound structure where the stack is wound along the first direction. A length L corresponding to a difference between the second and first widths, a mass per unit area M.sub.a of the negative electrode active material-containing layer, and a ratio p/n of a capacity p of the positive electrode to a capacity n of the negative electrode satisfy a relationship of 40 mg/m≤(L×M.sub.a)/(p/n)≤60 mg/m.

A solid electrolyte including: a lithium ion inorganic conductive layer; and an amorphous phase on a surface of the lithium ion inorganic conductive layer, wherein the amorphous phase is an irradiation product of the lithium ion inorganic conductive layer. Also, the method of preparing the same, and a lithium battery including the solid electrolyte.

A solid electrolyte including: a lithium ion inorganic conductive layer; and an amorphous phase on a surface of the lithium ion inorganic conductive layer, wherein the amorphous phase is an irradiation product of the lithium ion inorganic conductive layer. Also, the method of preparing the same, and a lithium battery including the solid electrolyte.

An electrolyte additive for a lithium secondary battery, an electrolyte, and a lithium secondary battery, the additive comprising a compound represented by Formula 1 below: ##STR00001##

A solid electrolyte represented by general formula Li.sub.ySiR.sub.x(MO.sub.4), where x is an integer from 1 to 3 inclusive, y=4−x, each R present is independently C1-C3 alkyl or C1-C3 alkoxy, and M is sulfur, selenium, or tellurium. Methods of making the solid electrolyte include combining a phenylsilane and a first acid to yield mixture including benzene and a second acid, and combining at least one of an alkali halide, and alkali amide, and an alkali alkoxide with the second acid to yield a product d represented by general formula Li.sub.ySiR.sub.x(MO.sub.4).sub.y. The second acid may be in the form of a liquid or a solid. The phenylsilane includes at least one C1-C3 alkyl substituent or at least one C1-C3 alkoxy substituent, and the first acid includes at least one of sulfuric acid, selenic acid, and telluric acid.

A solid electrolyte represented by general formula Li.sub.ySiR.sub.x(MO.sub.4), where x is an integer from 1 to 3 inclusive, y=4−x, each R present is independently C1-C3 alkyl or C1-C3 alkoxy, and M is sulfur, selenium, or tellurium. Methods of making the solid electrolyte include combining a phenylsilane and a first acid to yield mixture including benzene and a second acid, and combining at least one of an alkali halide, and alkali amide, and an alkali alkoxide with the second acid to yield a product d represented by general formula Li.sub.ySiR.sub.x(MO.sub.4).sub.y. The second acid may be in the form of a liquid or a solid. The phenylsilane includes at least one C1-C3 alkyl substituent or at least one C1-C3 alkoxy substituent, and the first acid includes at least one of sulfuric acid, selenic acid, and telluric acid.

An organic electrochemical cell includes a cathode including a quinone compound, an anode including dipotassium terephthalate, an electrolyte, and a separator disposed between the anode and the cathode, the organic electrochemical cell configured such that, during a discharging operation, potassium ions travel through the separator and the electrolyte to the cathode.